In order to perform a retrospective study on the feline respiratory diseases, the individual records of the Veterinary Hospital at the Universidad Austral de Chile between 1997 and 2004, were analyzed. A total of 2,068 clinical records were examined, of which 291 were identified as respiratory diseases. Most cases were observed in male felines of less than 1 year-old (53.8%), from 1 to 5.9 year-old (57.8%), and among female felines of 6 years of age and older (64.7%). The most affected topographic area was the upper respiratory tract (57.1%), most likely to occur in felines of less than 1 year-old (58.5%). Feline Respiratory Syndrome was the most frequent diagnosis (128 cases) with a high rate of cases in male felines of less than 1 year-old (56.4%), from 1 and 5.9 year-old (54.3%) and among felines of 6 years of age and older (75.0%). The frequency of respiratory diseases increased during August (13.7%). Feline Respiratory Syndrome had more cases during March (11.7%) and September (12.5%). The respiratory disease endemic index during the study period showed an epidemic curve in March, April, May, July, November and December of 2002. Regarding Feline Respiratory Syndrome, there was an epidemic curve in March, April, June, July, November and December of 2002. It was concluded that respiratory diseases affected more frequently male felines of less than 1 year-old; being the upper respiratory tract the most affected area; Feline Respiratory Syndrome was the most frequent diagnosis and the frequency of feline respiratory diseases varied according to month of the year.